Current power transfer of bicycles has two different forms, one uses a chain for power transfer, and another is chainless. The trading power of a driver applied to a crank of a bicycle is transferred to the rear wheel by a chain or chainlessly so as to drive the bicycle to move.
Currently, clutches of bikes are hidden within hubs of the bikes and are only suitable to bikes with chains, while currently no internal clutch is provided for chainless bikes; and thus no suitable driving device for guiding power out of the hub to transfer into the hubs.
With reference to FIG. 1, conventionally, the supporting structure of the hub A1 of the internal clutch is supported by the lateral covers A2 and A3 to be installed on a fixing shaft A4. The bearings A5 are installed between the hub A1 and the lateral covers A2 and A3. A bearing A6 is installed on a position between the lateral cover A2 and the fixing shaft A4 so that the lateral cover A2 is freely rotatable. The rotatable lateral cover A2 thus serves to transfer power out of the lateral cover into the cover to drive the internal clutch to rotate. In this conventional structure, the bearing 6 is used for rotation of the lateral cover A2. However, this structure causes that the supporting structure needs higher precision and more complicated design for achieving the requirement of stability and power transfer. As a result, the structure is complicated and the cost is high. Furthermore, the overall manufacturing works are more and more complicated and cost in assembling is thus increased.
Therefore, there is an eager demand for an internal clutch installed within the hub for using to a chainless bike, in that it has a compact and simple structure for power inputting to the hub for driving the internal clutch.